Question

In $50gm$ alloy of gold and silver. The gold is $80\%$ by weight. How much gold should be mixed to this alloy so that the weight of gold would become $95\%$?

• A. 200$gm$
• B. 150$gm$
• C. 50$gm$
• D. 10$gm$

Answer 1

The correct option is B 150$gm$

$Accordingtoquestion,quantityofgoldinalloy$

$\frac{80}{100}\times 50=40g$

$Letxgofgoldismixedwiththisalloy.$

$\frac{40+x}{50+x}\times 100=95$

$=>4000+100x=4750+95x$

$=>x=\frac{750}{5}=150g$